Well.... obviously he/she should be able to:
-Raise healthy and happy cows that he will always get the highest prices for at sale time. Although the health of a cow is usually easy to identify, making sure they're happy is somewhat harder since it requires excellent cow communications skills and some knowledge of cow psychology. Since the good cattleman will be an expert in time management he will also know how to use flag signals/semaphore when conducting group or whole herd psychology sessions from the roof of his pickup truck in the pasture.
-Negotiate the best possible price for replacements, bulls or otherwise. The seller should feel guilty if he doesn't just give the "good cattleman" the cow/calf/bull etc.. In short, the good cattleman will be able to BS his way into or out of any situation.
-Predict the weather with absolute accuracy and know rain dances that work when needed.
-Understand all aspects of soil and forage analysis.
-Set a bone, thread a needle, fix an engine, climb and fall-off a windmill, barn, or other structure and be ale to laugh about it while everyone else is laughing at him.
-Run faster than a speeding bullet (or at least a bull), jump tall buildings/ hay bales in a single bound.
-Enjoy the sight of a newborn calf, and watching the grass grow.
I'm sure there are more, but since I'm not there yet how would I know?